Roofing contractors in Minnesota say they’ve noticed an uptick in roofs collapsing this winter because of the record amounts of snow — and we’re not just talking about the Metrodome.

Investigators and Apple Valley say it’s too early to say what caused a church’s two-year-old roof over its gymnasium to cave early Friday. Earlier this week, a hardware store’s roof in Glenwood gave way to snow.

James Kirby of with the National Roofing Contractors Association says many of the cases he’s heard about this winter nationally can be explained by simple physics.

“I don’t think there’s too much question about the coincidence of really heavy snow and roof collapses,” he said.

Even light and fluffy snow can build up, especially along corners and parapets, Kirby said, and continuous snowfalls makes the situation even worse.

“If you get one bad snow a year, and a foot of snow up on your roof, that’s one thing,” he said. “If you get these one-foot snows a week apart — three, four, five times, — then you get to the point where you’re potentially overloading the capacity of the roof. We’re just not used to these heavy snowfalls, and so many of them.”

In Apple Valley, investigators say the church staff noticed cracks in the drywall and ceiling a week ago, and closed the gym. A general contractor was supposed to examine the building today, but it was too late.